Improvement in lightning-rods



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J. PRATT.

Lightning Rod.

Patented Dec. 27, 1864.

UNITED STATES JAMES PRATT, OF CHICAGO, ILLINOIS.

IMPROVEMENT IN LIGHTNING-RODS.

Specification forming part of Letters Patent No. 15,632. dated December27, 1864.

To all whom it may concern:

Be it known that I, JAMES PRATT, of Chicago, in the county of Cook andState of Illinois, have invented a new and useful Improvement inLightning-Conductors; and I do hereby declare that the following is afull, clear, and exact description of the same, reference being had tothe accompanying drawings and the letters and figures marked thereon,which form part of this specification.

In the said drawings, Figure 1 represents a view of the interior portionof my improved lightning-conductor; Fig.2, a "iew of a section orportion of the continuous copper strip wherewith the part shown in Fig.1 is inclosed; Fig. 3, view of the conductor when completed; Fig. 4, aview of the points affixed to the said rod or conductor at the top.Figs. 5 and 6 are top and side views, respectively, of the insulatorwhich I use in putting up my improved conductors, and Fig. 7shows myinvention as attached to a house and in use.

The nature of my invention consists in novel mode of inclosing thecentral core of continuous twisted wires (marked A) with a continuousstrip of copper, thereby inclosing said core of twisted wires in acopper tube which is continuous and unbroken, which is much cheaper thanthe ordinary mode of iuclosing said core with a rigid tube of copper puttogether by joints, and is at the same time a much safer conductor, inconsequence of the continuous nature of the same, and, besides, can becoiled up like ordinary wire, and hence can be put up at a much lessexpense of time and labor than the conductor formed by rigid and jointedtubing of copper.

To enable those skilled in the art to make, exercise, and use myinvention, I will proceed to describe the same with particularity.

The central portion of my conductor, A, is formed by twisting or windingtogether several wires (marked a) of suitable size and numher to formthe core of the desired diameter, which is generally one-half of aninch. These wires are cut of sufficient length to make the conductor ofthe proper length for each particular place in which the same is to beused.

I then take a strip of copper, B, of the same length of the wiresaforesaid, or rather of such length that when wound around said centralcore obliquely, in the manner shown in the drawings, it will completelycover the same, and wind said copper strip around the cord of twistedwire obliquely in such a manner (the said strip being of the properwidth and varying with the size of the central cord) that the said wiresare compactly inclosed as by a continuous tube, while at the same timeits pliability will permit the whole to be coiled up for transportationand readily uncoiled for use. Fig. 3 shows the conductor after the saidcopper strip is wound about the wires.

Figs. 5 and 6 represent the insulators used by me, although I do notclaim them as myinvention.

D represents a glass block fastened to the house by the screws (1.

F is a zinc plate fastened upon the end of said block, and b b are wirespassing through said plate E, by means of which the conductor is firmlyattached to the insulators by twisting them around the same.

4 Having now fully described my improved lightning-conductor, I willspecify what I claim as new therein and desire to secure by LettersPatent- Inclosing the cord of continuous twisted wires with acontinuouscopper strip,arranged and operating substa-tially as and for thepurposes herein shown and described.

JAMES PRAT I.

Witnesses:

N. E. MARRs,

F. H. BROWN.

